Response Spectrum Modal Pushover Method for Estimating Seismic Demands

In this study, a new modal pushover analysis procedure (MPPRS), which takes into account the effect of the higher modes of vibration, is presented. The advantage of the proposed MPPRS is its use of the design response spectrum instead of using the nonlinear dynamic analysis stated in the original MPA Method. To illustrate the application of the proposed MPPRS, three RC frame buildings, which are modeled as 2D moment-resisting frames of 8, 12, and 16 stories, are analyzed. The RC frames are subjected to four natural earthquakes scaled to different PGA values, as well as two artificial earthquakes compatible with the design response spectrum. About 36 NLDA are executed together with 36 analyses by the MPA and 36 analyses by the proposed MPPRS in order to illustrate the validity of the MPPRS to estimate the seismic demands. Target roof drift, the peak floor displacements, the peak inter-story drift ratios, the target base shear, and the plastic hinge distribution are estimated. In all analyses, the effect of the higher modes of vibration is considered and examined. Results show the effectiveness of the proposed MPPRS in estimating the seismic demands of the RC buiding frames.